Capt. Richard Conklin said the most recent spike of drug-related deaths is being investigated and there appears to be no connection between the men.

The recent surge compares to a single day in July when two men and a woman were treated for overdoses in Stamford. One of the men died.

“Unfortunately, regionally and nationally, we are seeing terrific problems with opioids, heroin, fentanyl and pain killers. Recently in the past week, we see three cases that present and appear to be overdoses,” said Conklin, adding that the Office of the Chief Medical Examiner has not made final determinations on what caused the deaths.

“We caution people using opioids,” he said. “You are buying drugs on the street and there is no government regulation — you don’t know what is in it.”

Conklin said police will not release the names of the victims until the investigations are completed.

Evidence found at the scene, including drug paraphernalia, needles and drugs make it likely that each of the deaths will be found to be from overdoses involving heroin or heroin cut with fentanyl, which can be 50 times more powerful than heroin, Conklin said.

“Usually, when you see a spike like this, a betting man would say there is fentanyl involved,” Conklin said.

Conklin said the heroin did not appear to be from the same batch as the bags containing the drugs lacked similar identifying stamps.

On Sunday night, police were called to the home of a 31-year-old man on Spring Street. He was found dead after apparently snorting heroin. His drug history is unknown.

On Wednesday, police were called to the home of a 44-year-old Wooridge Drive man. The man appeared to have been using the drug with a needle and was found dead in the bathroom, Conklin said.

On Thursday night, police found the body of a 54-year-old man in his Home Court home in the Cove who appeared to have ingested the heroin intravenously. Conklin said the man had a long drug history. Conklin said the man could have died anytime in the last week, when he was last seen.

Conklin said the department now has four officers in the major crimes bureau specially trained to investigate overdose deaths.

One of those officers, Michael Franzetti, assembled a case in August, charging 65-year-old James Pipicelli with manslaughter following the July overdose death of Daniel Peretz, 28.

“Unfortunately, it is a sign of the times that we have investigators designated and trained to follow up on these drug overdoses. Three in our community within in a week is a terrible situation,” Conklin said. “We will follow up on these and hopefully determine their sources for the heroin and if possible obtain arrest warrants for those responsible.”